Is your machine an Auto?
I hear that sound almost every morning. In fact the Kawasaki Prarie 360 will generally be much louder and more sick sounding.
Sorry I lack the knowledge of a more technical answer but I have not the prose. If your machine is an automatic it is your clutches and is very typical. If your Eiger is a 5 speed see your dealer asap. A phone call and an experianced ear will not hurt in any case. I would haul it down to the dealer if it were mine, just to be sure.